Link: LineageOS

Thinking about trying this one, as 1) It is the only reasonable way to get "userdebug" outside Nexus/Pixel, and 2) OnePlus 3, which I spare, looks like well-supported.

Why userdebug? Because it provides more comprehensive Systrace data than typical "user" build. System-level tracing is essential to any performance investigation.

via LineageOS – LineageOS Android Distribution